Near complete visual recovery and refractive stability in modern corneal transplantation: Descemet membrane endothelial keratoplasty (DMEK)

Abstract

Objective

To report the 6 months results of a large prospective study on Descemet membrane endothelial keratoplasty (DMEK) for management of corneal endothelial disorders.

Methods

DMEK was performed in 300 consecutive eyes with Fuchs endothelial dystrophy, bullous keratopathy or previous corneal transplant failure. Best spectacle corrected visual acuity (BSCVA), refractive outcome and endothelial cell density (ECD) were evaluated before and at 1, 3, and 6 months after surgery. Intra- and postoperative complications were documented.

Results

At 6 months, 98% of eyes reached a BCVA of ≥20/40 (≥0.5), 79% ≥20/25 (≥0.8), 46% ≥20/20 (≥1.0), and 14% ≥20/18 (≥1.2) (n = 221). The pre- to 6 months postoperative spherical equivalent (SE) showed a +0.33D (±1.08D) hyperopic shift (P = 0.0000). Refractive stability was shown at 3 months after DMEK, i.e. no significant change in SE (P = 0.0822) or refractive cylinder (P = 0.6182) at 3 versus 6 months follow-up. Donor ECD showed a decrease from 2561 (±198) cells/mm² before, to 1674 (±518) cells/mm² at 6 months after surgery (n = 251) (P = 0.0000). The main complication was (partial) graft detachment occurring in 31 eyes (10%). Secondary ocular hypertension was seen in 13 eyes (6%): 6 induced by air-bubble dislocation posterior to the iris and 4 induced by steroids. Secondary cataract requiring phaco-emulsification developed in 3 out of 63 (5%) phakic eyes.

Conclusions

DMEK may provide a refractively neutral near complete, rapid visual rehabilitation with ECDs similar to earlier endothelial keratoplasty techniques. This combined with a relatively low complication rate, would indicate that DMEK is a safe and effective treatment for corneal endothelial disorders.

Introduction

From 1998, the authors have introduced various sutureless techniques for the replacement of diseased corneal endothelium. These techniques have been popularized as ‘deep lamellar endothelial keratoplasty’ (DLEK) [1], and ‘Descemet stripping (automated) endothelial keratoplasty’ (DSEK/DSAEK) [2], [3], [4]. More recently, the authors further refined the concept of endothelial keratoplasty towards the selective transplantation of Descemet membrane (DM) and its donor endothelium, referred to as ‘Descemet membrane endothelial keratoplasty’ (DMEK) [2], [5], [6], [7]. Furthermore, Studeny et al. described a hybrid technique between DSEK/DSAEK and DMEK, in which transplantation of Descemet membrane with a peripheral stromal rim is performed, referred to as DMEK-S or DMAEK [8].

The early forms of endothelial keratoplasty, DLEK and DSEK/DSAEK, may have shown that visual outcomes could compete with penetrating keratoplasty (PK), while the most frequent complications were minimized [9]. Endothelial keratoplasty shows minimally induced astigmatism because the recipient anterior corneal surface is not compromised; suture related problems are eliminated since endothelial keratoplasty requires no (corneal) sutures; and wound healing related complications are rare as the procedure can be performed through a self-sealing limbal or scleral tunnel incision.

Initial results showed that DMEK enabled better visual outcomes than DLEK and DSEK/DSAEK with minimal refractive changes [5], [6], [7], [10], [11], [12], [13]. Given the growing interest worldwide, optometrists may soon become more involved in the referral and postoperative management of these patients. Hence, the aim of the current study was to evaluate a first series of 300 consecutive DMEK cases, with the main focus on visual and refractive outcomes.